I sold all my MRX4R/X chassis for a song. The guy I sold it to got 2 rolling chassis and enough parts to build another for $200.
With an Engine like a Mega and a starter box, I would honestly pay no more than $300-350.
But I'm tight and I also don't buy 2nd hand cars.
Front shocks are all the same, MRX4-5. But the MRX4R shocks are different, they are longer in the body due to the different rear geometry the MRX4R had. They when back to the shorter shock bodies with the MRX4X which had the same rear geometry as the MRX4.
Good luck with the car, I've had every model from the MRX3 thru to the MRX5. You honestly can't get a better and easier to setup chassis.
Pilot the BEST MUGEN kills the rest.
Team Ball Banger Racing inc.
OS Speed R2101
Futaba 3PK (HRS) - Crystals still rock.
Old School for Old Fools.